Rice(Oryzasativa)issensitivetosalinity,butthesalttoleranceleveldiffersamongcultivars,whichmightresultfromnaturalvariationsinthegenesthatareresponsibleforsalttolerance.High-affinitypotassiumtransporter(HKTs)hasbeenproventobeinvolvedinsalttoleranceinplants.Therefore,wescreenedfornaturalnucleotidepolymorphisminthecodingsequenceofOsHKT1,whichencodestheHKTproteinineightVietnamesericecultivarsdifferinginsalttolerancelevel.Intotal,sevennucleotidesubstitutionsincodingsequenceofOsHKT1werefound,includingtwonon-synonymousandfivesynonymoussubstitutions.Furtheranalysisrevealedthatthesetwonon-synonymousnucleotidesubstitutions(G50TandT1209A)causedchangesinaminoacids(Gly17ValandAsp403Glu)atsignalpeptideandtheloopofthesixthtransmembranedomain,respectively.Toassessthepotentialeffectofthesesubstitutionsontheproteinfunction,the3DstructureofHKTproteinvariantswasmodelledbyusingPHYRE2webserver.Theresultsshowedthatnodifferencewasobservedwhencomparedthosepredicted3DstructureofHKTproteinvariantswitheachother.Inaddition,thecodonbiasofsynonymoussubstitutionscannotclearlyshowcorrelationwithsalttolerancelevel.Itmightbeinterestingtofurtherinvestigatethefunctionalrolesofdetectednon-synonymoussubstitutionsasitmightcorrelatetosalttoleranceinrice.
